1 In The Nature of Science, Part 1, we discussed the early steps of the scientific method. After conducting the experiment, you need to begin your analysis. Scientific analysis includes measurement. Remember, when you measure, you compare an aspect of an object or event with a standard unit. Scientists worldwide use the International System of Measurements or SI which is based on intervals of 10 (metric system). This system includes the standard measurement for length, mass, temperature, and volume. Scientists look for accuracy and precision in their measurements. Accuracy represents how close a measurement is to the true value of the object or event being measured. Precision is the exactness of a measurement. For example, measuring the amount of nonfat lasagna eaten by the freshmen in pounds may be less precise than measuring that same amount in ounces. French fries may be another story!2 Scientific measurement also focuses on error of measurements and models to help obtain those measurements. Error is the expression of the amount of imprecision or change in a set of measurements. This is usually written as percentage error or confidence interval. The confidence interval describes a range of values for a specific percentage of measurements. Percentage error is calculated using the following equation:

Models are used to simulate conditions in nature. They can be a description, representation, or imitation of objects, systems, and events in nature. There are five types of models: conceptual models, mathematical models, computer models, physical models, and graphical models.3 After scientists finish their research, they present their findings to a peer review. A peer review includes scientists who are knowledgeable about the presenting scientist's field. They examine the scientist's results and conclusions to determine their validity. The panel can offer suggestions for improvement; state that the conclusions are faulty and recommend they not be published; or determine that the results are valid and should be published.